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Pond Dredging
& Silt Removal

Professional Silt Removal
Services in New Zealand

Stormwater ponds play a vital role in managing stormwater runoff from urban areas, and providing water treatment and retention to help prevent flooding. However, over time, these ponds can become filled with silt and debris, reducing their effectiveness both in water treatment and retention. To maintain the correct health of stormwater ponds and ensure they continue to function as intended, pond dredging is often necessary.

Stormwater pond dredging involves removing accumulated silt, leaves, vegetation, and other debris that can build up over time. This pond dredging process involves use of  SiteCare’s specialized dredging machines to extract and pump the silt and debris from the bottom of the pond without the need to empty the pond of water. The dredged silt is pumped into our sealed dewatering bins where the silt and water are separated. The water drains back to the stormwater pond and up to 12 tonnes of silt is captured in each bin.

Our hook trucks uplift the full bins and transport them off site for emptying.

This system is extremely versatile and enables stormwater pond dredging to be undertaken in urban locations with restricted space and access.

There are several reasons why it is important to perform pond dredging for effective silt removal from stormwater ponds:


Maintaining Capacity

Pond dredging and built-up silt removal helps restore the pond’s storage capacity, allowing it to hold more water during heavy rain events. This helps reduce the risk of flooding in nearby areas and can prevent damage to nearby homes and businesses.

Protect Water Quality

Silt can contain pollutants and excessive nutrients such as Phosphorus and Nitrogen that can be harmful to the environment. If allowed to accumulate, these pollutants can affect the pond water equilibrium and quality. Regular silt removal by undertaking pond dredging can help to protect water quality and the supporting ecosystem. The presence of excessive nutrients can cause poor water quality, seasonal algae blooms and water eutrophication.

Maintain Stable Water Temperature

Accumulated silt can interfere with the volume ratio of silt-to-water and when the water volume is sufficiently reduced this can cause water temperatures to rise and create conditions that support undesirable bacteria that can cause botulism.
Botulism is a serious and potentially deadly condition that can occur in ponds and other bodies of water. It is caused by a toxin produced by the bacterium Clostridium botulinum, which can grow in the anaerobic (oxygen-deprived) conditions found in silt at the bottom of ponds and eutrophic water conditions. The bacteria produce spores that can remain dormant for long periods of time, but when conditions become favourable (such as during a period of warm weather or a sudden influx of organic matter), they can begin to grow and produce the botulinum toxin.
This toxin can then be ingested by fish, waterfowl, and other animals that live in or around the pond, leading to botulism. Silt removal by undertaking pond dredging can help to manage and contain levels of organic material, nutrients, and lower water temperature to help prevent botulism outbreaks.

Why Trust SiteCare for Your Silt Removal Project?

SiteCare have been delivering professional sludge removal
services throughout New Zealand for over 20+ years.

However, stormwater pond dredging and silt removal are not without its challenges. It is important to carefully plan the dredging process to minimize the impact on the surrounding environment. This may involve using sediment control measures to prevent the release of sediment into nearby water bodies, or carefully timing the dredging to avoid disturbing sensitive wildlife.

Overall, stormwater pond dredging is an important part of maintaining healthy and functional water management systems in urban areas. By removing accumulated silt and debris, pond dredging helps ensure that stormwater ponds continue to provide the benefits of flood protection and water quality improvement for years to come.


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